Lake Mission ViejoAdvanced Purified Water

Treatment Facility

April 21, 2016

Santa Margarita Water District• Provides Water and Wastewater Service to 

over 155,000 residents• Over Next 20‐30 years ~40,000 More 

Residents

SMWD Service Area

Indoor Use12,100 AF

(February low flows)

24,000 AFPotable Water

Ocean Outfall3,130 AF

Recycled Water7,600 AF

Chiquita  – 4,000 AFOso Creek ‐ 1,800 AF3A WRP ‐ 1,800 AF

Urban Return Flows1,800 AF

Oso Barrier ‐ 1,120 AFHorno Basin ‐ 180 AFTrabuco ‐ 300 AFDove Canyon ‐ 200 AFGobernadora ~ 1,250 AF

SMWD 2015 Water SupplyWastewater

Chiquita ‐ 6,500 AFOso Creek ‐ 1,980 AFSOCWA ‐ 2,250 AF

Outdoor Use9,400 AF

(18,300 AF)

RECYCLED WATER PROJECTS

• Califia – 220 afy• Coto de Caza – 400-1,250 afy• Palmia – 70 afy• Lake Mission Viejo APWTF – 300 afy• Misc. Conversions

• Hidden Ridge – 35 afy• Lake Mission Viejo – 50 afy• City of Mission Viejo – 50 afy

• Las Flores – 220 afy• Melinda Road – 150 afy• Rancho Santa Margarita – 1,000 afy

Lake Mission ViejoAdvanced Purified Water Treatment Facility

Project Background• Lake Refill ~ 600 afy

• Rainfall ~ 100-300 afy• Groundwater ~ 150 afy• Potable Make Up Water ~ 150-350 afy

• Provide Sustainable Make Up Water• Drought proof• Avoid regulatory restrictions

• Cost Effective• Implementable

• Proximity to District Facilities

Finisterra Pump Station

Pump Station

Zone B Reservoir

Access Road

Looking East Across Reservoir at Pump Station

Looking North West at Finisterra Pump Station

Looking West Across Reservoir

Lake Mission ViejoAPWTF - Components

• Process Feed Pumps• Remove “larger” solids • 475 gpm• >200 micron

Pre Screening

• Protect RO membranes

• 475 gpm

UltraFiltration(UF) • Verify no free 

chlorine• pH adjustment for ammonia/nitrogen removal

Chemical Conditioning

• Remove TDS• Remove NH3/NO2

• pH adjustment

Reverse Osmosis(RO) • 375 gpm

• Pathogen Removal

• No chlorine residual

UV Disinfection

• If determined to be necessary

Nitrate Removal(TBD) • Lake Mission 

Viejo• Improve RW System  WQ

Effluent Discharge

Brine ~ 130,000 gpd

BW ~ 35,000 gpd

Lake Mission Viejo Preliminary Process Diagram

Lake Mission Viejo APWTF Preliminary Site Plan

Lake Mission Viejo - Advanced Purified WaterEstimated Cost of Water

ITEM Annual Cost 300 AF/YR

CapEX@ $5.1 m – 20 yrs. @ 2.5% ‐3.75% $300,000 $1,000

O&M Costs

Electrical $  66,000

Chemical $  61,000

Repair & Replace $129,000

Labor $150,000

Subtotal O&M Costs(1) $406,000 $   680

Cost of Source Water $ 320

Cost of APW ($/AF) $2,000

MWD – LRP Contribution ($475)

Effective Cost of APW ($/AF) $1,525(1) Assumes operating costs spread over 600 af/yr production

Project Financing

• City of Mission Viejo• $1 million grant• $3 million low interest loan

• Santa Margarita Water District• $1.1 million loan

• Lake Mission Viejo Association• Repays CapEX with monthly fixed charges• Pays operating costs for only that APW provided

• Metropolitan Water District• LRP - $475/af, 15 years